Envelopes or sacks adapted to contain substances from which an infusion is to be made have been known in the art for some time. For example, U.S. Pat. No. 2,137,243, issued to Haymon on Nov. 22, 1938 discloses a closed envelope made from perforated cellulose sheets through which water is able to quickly and efficiently permeate to form an infusion comprised of hot water and ground coffee, tea leaves, or other substances which have constituents partly or wholly soluble in hot water.
U.S. Pat. No. 4,572,360, issued to Lischka, geb. Woitzik on Feb. 25, 1986 discloses another infusion package for bathing herbs. The latter package preferably comprises a pouch made of synthetic foil having perforations which form projections extending beyond one surface of the synthetic foil. Some of the projections are oriented toward the interior of the package, while others are oriented outwardly from the package. According to the teachings of this reference, the outwardly extending projections widen when the package sides are pressed together. Conversely, when the inside space of the herb package increases, the inwardly oriented projections are enlarged somewhat, while the outwardly oriented projections tend to close up. This produces a valve-action which allegedly produces a very homogeneous water flow through the inside space of the herb package. It is in this manner that the herbs impart their active substances into the water, yet remain within the pouch so that they can later be removed from the water bath without difficulty.
Still another infusion bag for particulated food or beverage products such as tea, coffee and the like is disclosed in U.S. Pat. No. 4,605,123 issued to Goodrum et al. on Aug. 12, 1986. The infusion bag of Goodrum et al. is constructed of a tube of perforated thermoplastic film or other porous material having a central product containing portion and flat end portions on each end thereof. The perforated thermoplastic film or other porous material has a multiplicity of minute holes or openings which are described as being sufficiently small in size to prevent migration of the particulated food product therethrough, yet sufficiently large in size and number to permit adequate fluid flow therethrough. Joining together of the flat end portions forms a flow through or dual container type infusion bag and a handle for extending over the side of a cup or pot.
The use of closed envelopes or sacks to add detergent composition to the wash water during an automatic laundering cycle are also generally known in the art. For example, U.S. Pat. No. 4,188,304 issued to Clark et al. on Feb. 12, 1980, discloses the use of a detergent product in particulate form housed within a closed, water insoluble bag which has a water sensitive seal. The contents of the bag are discharged during the wash cycle when the water sensitive seal opens upon contact with the wash water.
Water insoluble bags or envelopes containing a detergent composition and having a water permeable layer protected by a water soluble or water dispersible protective layer are also generally known in the art. See, for example, U.S. Pat. No. 4,348,293 issued to Clark et al. on Sept. 7, 1982. The water soluble or water dispersible material also serves to prevent dusting out of the detergent composition through the water permeable portion of the bag so long as the bag remains in a dry state.
U.S. Pat. No. 4,416,791 issued to Haq on Nov. 22, 1983, discloses another pouched detergent composition wherein the pouch is made from a packaging film comprising a base film which is at least partially water soluble and which carries on one side a protective layer of particulate inert plastic material having a high water repellency. The pouch is made so that the interior surface having the layer of particulate contacts the detergent composition. In use in the washing machine, the unprotected pouch surface is attacked by the wash liquor to release the contents, while the protective layer allegedly prevents attack of the interior of the package by the contents prior to use.
Other representative prior art products containing a detergent type material within an envelope which is capable of allowing the entry of water during the wash cycle and dispensing of the dissolved detergent are disclosed in U.S. Pat. No. 4,410,441 issued to Davies et al. on Oct. 18, 1983; U.S. Pat. No. 4,433,783 issued to Dickinson on Feb. 28, 1984; and U.S. Pat. No. 4,515,703 issued to Haq on May 7, 1985.
Pouched products for dispensing various types of laundry additives, such as softeners, anti-stats and bleaches during the drying cycle in an automatic clothes dryer are also known in the art. See, for example, U.S. Pat. No. 4,114,284 to Weber et al. disclosing a sachet consisting of a closed packet of semipermeable to gas plastic film containing an odor producing composition of a fragrant nature absorbed on an inert absorbent carrier; U.S. Pat. No. 4,139,475 issued to Schwadtke et al. on Feb. 13, 1979 disclosing a package comprised of film material and having a pillow-like form with one side impermeable to the aqueous additive substance contained therein and one side containing a multiplicity of slits through which the aqueous additive substance is distributed during the clothes drying cycle; and U.S. Pat. No. 4,395,261 issued to Lutz on July 26, 1983 wherein hydrogen peroxide is placed into a pouched type film container with a microporous, hydrophobic surface which is heated, whereby the hydrogen peroxide is vaporized and delivered to the interior of the dryer where it is available to bleach the textiles.
In addition to the foregoing patent references dealing primarily with washer only or dryer only type products, various types of products suitable for use through both the washer and dryer have recently been introduced to the market by at least two manufacturers of laundry products, one of these being The Procter & Gamble Company of Cincinnati, Ohio. For the most part, the products marketed by The Procter & Gamble Company have been comprised of a multi-compartmented envelope formed from a pair of porous layers comprised of paper or non-woven material. The compartments in the envelope typically encapsulate a particulate detergent and/or bleach composition and either a particulate or a printed form of a fabric softener/anti-stat. The detergent and bleach compositions are water soluble so that they can be dissolved in the wash water and dispensed in the washing machine, while the softener/anti-stat is substantially insoluble in water, but softens when exposed to the elevated temperatures normally encountered in an automatic clothes dryer.
Through the washer and dryer products of the type recently introduced by The Procter & Gamble Company offer the convenience of one step addition at the time the clothes are initially introduced into an automatic washing machine. The detergent composition is dissolved by the wash water during the washing cycle to form a wash liquor for cleansing and bleaching the textiles being laundered. The bleach composition (if present) is also dissolved by the wash water to provide a bleach solution for bleaching the articles during the wash cycle. The fabric softener/anti-stat, whether printed on one or more of the porous layers comprising the envelope or included as a particulate in one or more of the detergent containing compartments, remains substantially solid at the temperatures normally encountered during the wash cycle. If the softener/anti-stat is in particulate form, the particles are of sufficient size that they will not pass through the porous layers comprising the envelope during the wash cycle.
Upon completion of the washing cycle, the porous envelope, substantially emptied of detergent and bleach (if initially present), is transferred along with the laundered textiles into an automatic clothes dryer where the elevated temperatures employed during the drying cycle soften the fabric softener/anti-stat printed on or contained within the compartments of the porous envelope. The softened fabric softener/anti-stat material is thereafter distributed onto the textiles by repeated impact of the laundered textiles against the porous envelope during the tumble drying cycle.
While the aforementioned through the washer and dryer laundry additive products marketed by The Procter & Gamble Company have provided a marked advance over the prior art single function pouches used either for delivering detergent and/or bleach compositions in the washing cycle or dryer additive compositions in the drying cycle, it would nonetheless be desirable to increase the delivery efficiency for the dryer additive material without at the same time causing increased staining of the textiles to which the dryer additive is being applied.